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B. J. HALL ET AL ARC LAIIP FOR PHOTOGRAPHIC AND OTHER PURPOSES Filed April 1.. 1920 Patented Dec. 11, 1923.

UNITED sraras PATENT OFFICE.

BENJAMIN JAMES HALL, OF IEIEHZIIDENJJ EASTUOTE. AND CARL FREDERIK GRIMUR THORKELIN, OF LONDON, ENGLAND.

ARC LAMP FOB PHOTOGR-APHIC AND OTHER PURPOSES.

Application filed April 1,

To all whom it may concern:

Be it known that we, BENJAMIN JAMES HALL, subject of the King of Great Britain, residing at Fieldend, Eastcote, in the county of Middlesex, England, and CARL Fnnonarrc GRIMUR THORKELIN, subject of the King of Denmark, residing at 3 Wolseley Road, Crouch End, London, N. 8, England, have invented new and useful Improvements in Are Lamps for Photographic and Other Purposes, of which the following is a specification.

This invention has reference to are lamps of the enclosed type in which the arc is placed horizontally, the lamp being suitable for emitting the light from the arc in a downward direction, and also for burning with a long are suitable for photographic purposes.

According to this invention we place the carbons converging in a wide angle to each other with their lower ends passing through and into an arc enclosing chamber, where the points of the carbons meet. The upper part of this chamber is opaque and the lower part translucent.

Each carbon holder is pivoted on the lower end of an arm capable of swinging in the direction in which the carbons move for striking and maintaining the arc. These arms are pivoted or hinged and may be extended upwards beyond the point at which they are pivoted somewhat similar to a pair of scissors either, open or crossed. Or the arms may terminate at the pivot or pivots thus resembling a hinge.

The are is controlled, preferably, by a solenoid the iron core of which is suspended from the swinging arms by flexible connections passing over pulleys.

The are is further controlled by a blow magnet in proximity thereto in the usual known manner.

The invention is illustrated on the accompanying drawings.

Fig. 1 is a diagrammatical view showing our method of supporting the carbon holders and movin the carbons for striking and maintaining t e arc.

1920. Serial No. 370,467.

Fig. 2 is a similar view showing a. slightly modified form of our invention.

A represents the carbon holders, B the carbons, D the arc enclosing chamber into which the lower ends of the carbons pass, E the swinging arms to which the carbon holders are pivoted, and F the iron core of the solenoid H. The chamber D has holes in its sides which form guides for the pivoted carbons to slide in.

In the method shown by Fig. 1 the swinge0 ing arms E extend upwards beyond the point e at which they are pivoted, the iron core being suspended from these extended portions by the flexible connections 6 passing over the pulleys a.

At Fig. 2 we have shown the swinging arms E terminating at the pivot pointa. In this case the flexible connections 6 are attached to the arms preferably below the pivot point e each flexible connection. by 7 which the core F is suspended, passing. preferably, over two pulleys e, 2. Or the flexible connections may be carried to the solenoid core in any manner that will enable the carbons to move in accordance with the movement of said core.

ln order that the lamp may give powerful actinic rays for photographic purposes, the carbons are arranged at a wide angle, of substantially 130 degrees. The carbons are arranged to work with a long are, being widely separated, and provided with current of suitable voltage.

As the carbons burn away each arm E is moved pivotally to an equal extent by the 35 single solenoid so that the arc is maintained substantially central of the translucent bottom portion of the inclosing chamber D.

What we claim as our invention and desire to secure by Letters Patent is ein arc lamp for photographic purposes, comprising a chamber having a translucent bottom and guide holes in its upper part, two arms supported pivotally above the said chamber, carbons arranged at substantially an angle of degrees, the upper parts of the carbons being pivoted to the lower parts of the said arms and the lower parts of the holes, a solenoid included in circuit wi carbons be' slidahle in the said ide mg 51 the carbons and provided with a slidable core, guide sheaves, and flexible connections passmg over the guide sheaves and attached to the said arms and to the solenoid core so that the weight'of the said: core assists in moving the carbons apart.

In bestiinony whereof we have signed our names to this specification in the presence 10 of two subscribin witnesses.

BENJAMI JAMES um.

CARL FREDERlK GRIMUR THORKELIN.

Witnesses:

H. W. Dmon-Incmm,

E. J. Dmox llmmm 

